Search results for "rotation"
showing 10 items of 935 documents
Réduire les risques de sélection de résistances : de la théorie à la pratique, des pistes pour améliorer la durabilité des PPP
2013
National audience; La résistance est le résultat inéluctable de la sélection exercée par les PPP sur les populations de bio-agresseurs. À terme, on ne peut pas empêcher une résistance d’évoluer. Mais on peut retarder substantiellement cette évolution. Le point-clef à retenir pour ce faire est que plus une pression de sélection est répétée dans le temps et homogène, plus elle conduit rapidement et efficacement à une adaptation. Autrement dit, plus les techniques de contrôle déployées contre un bio-agresseur sont peu diverses, plus le risque de sélectionner rapidement une résistance est élevé. En agriculture, un exemple type d’application d’une pression de sélection homogène et répétée est de…
RIED. Revista iberoamericana de educación a distancia
2015
Los Massive Online Open Courses (MOOC) son una modalidad de formación virtual que está ya presente en el panorama educativo actual y que responde a una concepción determinada de e-learning. Las universidades están integrando como parte de su oferta formativa este tipo de formación o, al menos, se está debatiendo si se integra o no. Ante esto, se hace necesario calibrar cuáles deben ser sus características con el fin de configurar un tipo de formación virtual de calidad. Se considera que son necesarios instrumentos que avalen la calidad de los MOOC desde diferentes perspectivas, en este caso la pedagógica, ya que de ello dependerá el éxito y la consolidación de este tipo de e-learning. El ob…
Towards open access
2019
In accordance with the rotation principle of the Journal, our four-year term for editing the Scandinavian Economic History Review is coming to an end. It is time to pass the Journal on to the capab...
Alignment of linear molecules by short duration laser pulses
2005
Alignment of linear molecules is efficiently induced by strong linearly polarized laser pulses. In the case of short pulses with respect to molecular rotation, periodic alignment appears in field-free conditions after the extinction of the field. This manuscript presents three techniques where the value of allows to quantify alignment without molecular dissociation nor additional alignment. They use a weak time-delayed probe pulse which experiences the optical properties of an aligned sample and shows modification of its characteristics. The first of them measures a depolarization due to the birefringence of the sample. The second one is based on the defocusing produced by the spatial distr…
STUDIES OF VARIABILITY IN PROTO-PLANETARY NEBULAE. II. LIGHT AND VELOCITY CURVE ANALYSES OF IRAS 22272+5435 AND 22223+4327
2013
We have carried out a detailed observational study of the light, color, and velocity variations of two bright, carbon-rich proto-planetary nebulae, IRAS 22223+4327 and 22272+5435. The light curves are based upon our observations from 1994 to 2011, together with published data by Arkhipova and collaborators. They each display four significant periods, with primary periods for IRAS 22223+4327 and 22272+5435 being 90 and 132 days, respectively. For each of them, the ratio of secondary to primary period is 0.95, a value much different from that found in Cepheids, but which may be characteristic of post-asymptotic giant branch (AGB) stars. Fewer significant periods are found in the smaller radia…
Diversifying crop rotations with temporary grasslands: potentials for weed management and farmland biodiversity
2010
Fruchtfolgen können dazu dienen, die kontinuierliche Selektion von Unkrautarten zu verhindern, die an eine bestimmte Kultur angepasst sind. Dies könnte dem Unkrautmanagement, der Einsparung von Herbiziden, und der Biodiversität dienen. Heutige, sehr einfache Furchtfolgen könnten durch mehrjährige Futterkulturen diversifiziert werden. Die Einflüsse solcher mehrjähriger Kulturen auf Unkräuter wurden in vier Ansätzen untersucht : 1) Vegetationsaufnahmen auf 632 Feldern in Westfrankreich zeigten, dass die Unkrautzusammensetzung zwischen mehrjährigen Futterkulturen und einjährigen Kulturen stark variiert. Der Vergleich von Feldern vor, während und nach mehrjährigen Futterkulturen legte nahe, das…
Neutron Radiography Visualization of Solid Particles in Stirring Liquid Metal
2015
Abstract This paper presents the analysis of the first dynamic neutron radiography experiment that visualized motion of solid particles in liquid metal, which was stirred by a system of four counter-rotating magnets. The paper also contains the quantitative results derived from neutron images: the distribution of particle concentration, number of admixed particles and velocities as functions of the magnet rotation speed.
The influence of others’ actions on perspective taking: Poster
2021
The influence of others’ actions on perspective taking: Oral presentation
2021
A first-order phase transition for pulsar surface
2012
In this paper, we explain the existence of a possible first-order phase transition that may occur over the external solid crust of a pulsar, by means of an interpretation of a particular formal model (drawn from Theoretical Astrophysics) whose thermodynamical phenomenology shows a possible first-order phase transition (according to Landau’s Phenomenological Theory).